smallpox, lifespans

This is in reponse to 2 messages. First, regarding generating
viruses from their DNA. There is a rich history of generating vir
uses from nucleic acids. The one i'm most familiar with
is poliovirus, published in 1980. It has been carried out for
many viruses. sometimes the RNA is infectious as well. The perti
question is whether it has been carried out with a pox
virus. I don't know.
The other question had to do with lifespans. Some viruses
are viable for a long time, others not. It depends on the
virus . For HIV, it's more complicated, because your blood sample
would contain provirus, which could be infectious for a longer
time, but under less likely conditions.